Mine roof support means



A ril 22, 1969 w. w. PAYNE ETAL 3,439,503

MINE ROOF SUPPORT MEANS Filed April 28, 1966 Sheet Z of'4 April 22, 1969 w. w. PAYNE ETAL 3,439,508

MINE ROOF SUPPORT MEANS Filed April 28, 1966 Sheet & of4

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April 22, 1969 w. w. PAYNE ETAL 3,439,508

MINE ROOF SUPPORT MEANS Filed April 28, 1966 Sheet 5 of 4 April 1969 w. w. PAYNE- ETAL 3,439,508

MINE ROOF SUPPORT MEANS Sheet 4 or4 Filed April 28. 1966 33 FIGS.

United States Patent US. C]. 61-45 13 Claims ABSTRACT OF THE DISCLOSURE A mine roof support having front and rear units of side by side hydraulic props on separate front and rear bases, with a blast barrier plate extending transversely of the front unit and hingedly connected to the front base, a hydraulic jack inter-connecting the blast barrier plate and the front unit, and a hydraulic jack or two steering hydraulic jacks and a telescopic base frame inter-connecting the front and rear bases.

This invention is for improved mine roof support means primarily for gold mining.

In the extraction of gold bearing ore from mines it is usual to support the roof between the working face and the goaf by front and rear lines of props extending throughout the length of and parallel to the working face. The ore is extracted by drilling the face and loading with explosive material, which is then detonated. The props are protected from the blast by a sectional blast barrier extending the length of the face and connected to the front line of props, and extending from floor to roof.

The main purpose of the blast barrier is to prevent valuable ore being lost in the goaf, this being the area which is subsequently collapsed by the removal of the rear row of roof supporting props. Following each blast and removal of the dislodged ore, the rear row of props is removed and is reset to form a new front line of props, and the blast barrier sections are transferred to these props.

According to the specifications of our South African patent application No. 63/938 and our British patent applications Nos. 8724/ 62 and 7155/63 there is provided support means comprising a single front hydraulic prop on a base and to which is attached a blast barrier, the prop being coupled by hydraulic means to a rear single hydraulic prop on a base so that the two props can be advanced in step'like mannner towards the working face.

In this arrangement the two bases are flexibility interconnected so that the props are stable only in limited manner, and it will be realized that in severely inclined seams which are common in gold mining areas, this arrangement has created difiiculties since the instability of the props results in a tendency for the supports to drift down towards the lower end of the working face at times when the props are released from the roofs and are being advanced.

An object of the invention is to provide mine roof support means primarily for gold mining of such improved construction as to be inherently stable.

The invention provides a roof support structure comprising a front unit of a plurality of laterally spaced front props on a common front base and to which a blast barrier section it attached, a rear unit of a plurality of laterally spaced rear props on a common rear base, and telescopic actuator and guide means inter-connecting the two units. Conveniently the blast barrier is hingedly mounted for pivotal adjustment by a hydraulic jack to reduce its height. Conveniently also the telescopic actuator and guide means consists of a hydraulic jack and a telescopic inter-connecting base frame. The connections of this telescopic base frame to the units are conveniently hinge connections on horizontal transverse axes. A front hinge connection may embody swivel means permitting predetermined angular movement about a horizontal axis length of the structure between the front unit and the telescopic base frame. Movement may also be allowed on a vertical axis to permit steering of the support for which purpose there may be two laterally spaced hydraulic jacks interconnecting the two units.

Suitable valve controls for the hydraulic components may comprise one for the front props and the barrier jack, a second for the rear props, and a third for the interconnecting jacks. The blast barrier sections may have skid bases and flexible head pieces.

The above and other features of the invention set out in the appended claims are incorporated in the construction which will now be described as a specific embodiment with reference to the accompanying drawings in which:

FIGURE 1 is a side view of a mine roof support structure according to the invention.

FIGURE 2 is a plan view of the support structure.

FIGURE 3 is a diagrammatic plan view showing a plurality of the support structures in use.

FIGURE 4 is a side view of one support structure in working position.

FIGURE 5 is a similar view to FIGURE 4 partly operated ready for advancement.

FIGURE 6 is a further similar view showing part advancement of the structure.

FIGURE 7 is a still further similar view showing the structure ready for complete advancement.

FIGURE 8 is a diagram of a hydraulic circuit for the structure.

Referring to FIGURES 1 and 2 a mine roof support structure is provided comprising a front unit 1 of a pair of laterally spaced front hydraulic props 2, 3 on a common base 4 and to which a blast barrier section 5 is attached, by brackets StZ-5d and hinge pins 5e, 5 a rear unit 6 of a pair of laterally spaced rear hydraulic props 7, 8 on a common rear base 9, and telescopic actuator and guide means indicated generally at It) inter-connecting the two units 1 and 6.

The hydraulic props 2, 3, 7, 8 are conveniently of double acting type, see FIGURE 8, and they are retained in required vertical attitude by conical guides such as 11, 13, FIGURES 1, 2, and base rubber buffers such as 14, 15, these being to allow for tilting movements of the props, and to cause their return to vertical.

The two front props 2 and 3 are interconnected by a coupling bar 16 secured to them by shackle bolts 2a, 3a and which pivotally carries, by brackets 16a, 16b and pivot pin 17, the front end of the cylinder of a double acting hydraulic jack 18, the piston rod of which is connected by pivotal means, comprising brackets 19, 19a, socket 19b, and hinge pin 190, to the barrier section 5. The barrier section 5 may have a skid base (not shown) and at its upper end it has attached to it a flexible head piece 24 FIGURE 1.

The front base 4 is connected to the rear base 9' by telescopic frame means comprising a front box like component 21 and a spaced rail component 22, 22a the rails being braced by side webs 23, 24. The front component 21 is connected by hinge plates 25-250 and hinge pin 25d to the front base 4 conveniently through the intermediary of a swivel connection form by brackets 26, 26a and a swivel pin 26b on a horizontal axis, the axis of the hinge means 25-25d being transversely of the structure, and the axis of the swivel means 26, 2611 being longitudinally of the structure.

The spaced rail component 22, 22a is connected by hinge pin 27, sockets 27a, 27b and brackets a, 9b, to the rear base 9, this hinge means being on a horizontal axis transversely of the structure and parallel to the axis of the front hinge means 25d.

Disposed interiorly of the telescopic frames 21 and 22, 22a there is a double acting hydraulic jack 28 the piston rod of which is connected by a socket 29 to the front hinge pin 25:! and the cylinder of which is connected by a socket 30 to the rear hinge pin 27.

Hydraulic fluid is supplied to the front props 2, 3 and to the barriers hydraulic jack 18 through the intermediary of a manual control valve 31, FIGURES 2, 8, to the rear props 7, 8 through the intermediary of a manual control valve 32, and to the advancing hydraulic jack 28 through the intermediary of a manual control valve 33. The valves 31, 32 are inter-connected by known hydraulic interlock means shown in FIGURE 8 such that neither of the valves can be operated to lower their props unless the remaining props are set to the roof.

FIGURE 8 shows the manner in which the props 2, 3, 7, 8, the jacks 18 and 28, and the manually controlled valves 31 to 33, are inter-connected by hydraulic pipes to feed and return lines of a pump supply. Also indicated is that the manually controlled valves 31 to 33 are of known three position construction, and that check and convergence valves OH to CH4 and C0, C01 and filters F1 to F4 are also included in the circuit as shown in accordance with known hydraulic practice.

As shown in FIGURE 3, a plurality of the structures as above described are used in a line parallel to the working face WP and they are advanced step by step each in the following manner.

Starting with the working position shown in FIGURE 4, in which the props 2, 3, 7, 8 of both front and rear units 1, 6 are set to the roof, the blast barrier 5 is in vertical operative attitude, and a blasting operation takes place on the working face WF.

After the blasted material has been cleared, FIGURE 5, the valve 31, FIGURES 2, 8, is operated so that the props 2, 3 of the front unit 1 are released from the roof, FIGURE 5, and so that the barriers jack 18 is extended to tilt the barrier section 5 downwardly to a lower height.

The props 2, 3 of the front unit 1 and the barrier 5 are now in a suitable lowered position to be advanced without fouling the roof particularly if it is uneven, and at this stage the valve 33, FIGURES 2, 8, is operated to extend the advancing ram 28 so as to advance the front unit 1 and the blast barrier 5 to the forward position shown in FIGURE 6.

At this stage the valve 31, FIGURES 2, 8, is further operated to re-extend the props of the front unit 1 into condition supporting the roof R as shown in FIGURE 7 and also to further operate the barriers jack 18 to return the barrier section 5 into its initial upright position with its upper flexible head piece 20 bearing against the roof R.

Next the valve 32, FIGURES 2, 8, is operated to release the props 7, 8 of the rear unit 6 from the roof R as shown in FIGURE 7 to enable these props 7, 8 to be advanced which is accomplished by further operating the valve 33, to contract the advancing ram 28.

When the props 7, 8 of the rear unit 6 are thus advanced, the valve 32 is further operated to re-extend the props 7, 8 of the rear unit 6 into roof supporting engagement with the roof.

The structure is now in the same condition as in FIG- URE 4 ready for the next blasting operation, and so on.

It will be understood that the structure is stable due to the provision in each unit 1, 6 of the two props 2, 3 and 7, 8 each unit on its own base and by the fact that whenever one pair of props is released from the roof, the other pair of props is in roof supporting condition.

It will be further understood that whereas the telescopic base frames 21, 22 allow the necessary articulation between the two units, the front and rear hinge means 25, 27 permit relative movements between the front and rear units and the telescopic frames about transverse horizontal axes, and the swivel means 26 permits relative movement between the front unit and the frame members and the rear unit about a horizontal axis longitudinally of the support. However no free relative movement is allowed between the two units and the telescopic frames about a vertical axis thereby preventing drift of the units down an inclined working face when the units are advancing.

In a modification, predetermined angular movement about a vertical axis of the front unit relative to the telescopic frames and the rear unit may be provided for steering purposes, the steering being effected by the provision of two advancing jacks instead of one, each of which is individually controlled. This will not allow drift down the working face since the front unit will be under positive control of the two advancing jacks.

The prop operating valves may have, embodied in the circuit, intensifying means according to our British Patent No. 980,001 to provide setting pressure of the props to the roof greater than that normally supplied by the liquid pressure lines feeding the hydraulic system.

We claim:

1. In a mine roof support, in combination, at least one prop adapted for roof supporting engagement with the roof, a blast barrier plate extending lengthwise the prop in a substantially vertical plane, hinge means interconnecting the blast barrier plate and the prop on a horizontal axis, and a fluid actuator connected to the prop and pivotally connected to the blast barrier plate at a location spaced from the hinge for displacing the blast barrier plate between substantially vertical and inclined positions.

2. In a mine roof support, in combination, at least two spaced props adapted for roof supporting engagement with the roof, a base commonly supporting the two spaced props and having opposite end parts, a blast barrier plate extending along the props and base, hinge means interconnecting the blast barrier plate and the opposite end parts of the base on a horizontal hinge axis, a coupling bar interconnecting the two props, and a fluid actuator interconnecting the coupling bar pivotally and the blast barrier plate spaced from the hinge axis.

3. In a mine roof support, in combination, at least one prop adapted for roof supporting engagement with the roof, a blast barrier plate extending lengthwise the prop in a substantially vertical plane, hinge means interconnecting the blast barrier plate and the prop on a horizontal axis, means for pivotally displacing the blast barrier plate on the hinge means between substantially vertical and inclined positions, and a flexible extension on the upper end of the blast barrier plate for flexing engagement with the roof when the blast barrier plate is in the substantially vertical position.

4. In a mine roof support, in combination, a front telescopic pro-p adapted for extension to support the roof and for contraction to release from the roof, a rear abutment, telescopic means interconnecting the front prop and the rear abutment and adapted for extension to advance the front prop when contracted using the abutment as an anchorage, a blast barrier plate extending along the front of the prop, hinge means connecting the blast barrier plate to the prop on a horizontal hinge axis, and means for displacing the blast barrier plate on the hinge means between an erect position engaging the roof when the prop is extended and an inclined position spaced from the roof when the prop is contracted.

5. The combination as claimed in claim 4 wherein the telescopic means comprises a front box-like component, front hinge means connecting this component to the front prop, a rear laterally spaced rail component slidable in the box-like component, rear-hinge means connecting the rail component to the rear abutment, a hydraulic jack extending in the telescopic means, and sockets on the ends of the jack and connected to the front and rear hinge means respectively.

6. In a mine roof support, in combination, front and rear spaced telescopic props adapted for extension to support the roof and for contraction to release from the roof, front and rear bases supporting the props respectively, a telescopic interconnecting base frame comprising a front box-like component, front hinge means connecting this component to the front base, a rear laterally spaced rail component slidable in the box-like guide component, rear hinge means connecting the rail component to the rear base, an advancing actuator extending in the components, sockets on the ends of the advancing actuator and connected to the front and rear hinge means respectively, a blast barrier plate along the front of the front prop, and means interconnecting the blast barrier plate and the front prop.

7. A structure according to claim 6 wherein the front hinge means embodies swivel means permiting predetermined any other movement about horizontal axis lengthwise of the structure between the front unit and the telescopic base frame.

8. In a mine roof support, in combination, a front unit of laterally spaced telescopic props, a rear unit of laterally spaced telescopic props, telescopic guide means and an advancing telescopic actuator interconnecting the two prop units, a blast barrier plate along the front of the front prop unit, attachment means attaching the blast barrier plate to the front prop unit, and a flexible extension on the top of the blast barrier plate.

9. A structure according to claim 8 having two laterally spaced hydraulic jacks inter-connecting the two units for allowing movement on a vertical axis to permit steering of the support.

10. A structure as claimed in claim 8 wherein said blast barrier plate has a skid base.

11. The combination of claim 8 wherein the attachrnent means is a hinge means attaching the blast barrier plate to a lower part of the front unit, and having an adjusting telescopic actuator interconnecting the blast barrier plate and the front prop unit spaced from the hinge means.

12. The combination of claim 8 having a base commonly supporting the front laterally spaced props, the hinge means connected to the base, a coupling bar secured to the front laterally spaced props, and the fluid actuator connected to the coupling bar.

13. A structure as claimed in claim 11 wherein said front and rear props and said adjusting and advancing telescopic actuators are hydraulic jacks, and having control valves comprising one for said front props and said adjusting telescopic actuator, a second for said rear props, and a third for said advancing telescopic actuator.

References Cited UNITED STATES PATENTS 3,320,751 5/ 1967 Groetschel 61-45 3,324,664 6/1967 Allen 61-45 3,201,943 8/1965 Wilkenloh et a1. 61-45 FOREIGN PATENTS 901,310 7/ 1962 Great Britain. 856,720 12/ 1960 Great Britain. 1,324,766 3/1963 France.

JACOB SHAPIRO, Primary Examiner.

US. Cl. X.R. 299 12 

